1. Field
A scroll compressor is disclosed herein.
2. Background
A scroll compressor is a compressor that forms a pair of compression spaces having a suction chamber, an intermediate pressure chamber, and a discharge chamber between a fixed wrap of a fixed scroll and an orbiting wrap of an orbiting scroll, in a structure in which the fixed scroll is fixed to an inner space of a casing and the orbiting scroll performs an orbital motion by being engaged with the fixed scroll. The scroll compressor is being widely applied to air conditioners, for example, as a refrigerant compressor device, owing to its advantages that a compression ratio is higher than other types of compressors, and a stable torque is obtainable as processes to suction, compress, and discharge a refrigerant are performed smoothly. Recently, a scroll compressor of high efficiency, which has a driving speed of more than 180 Hz by lowering an eccentric load has been developed.
The scroll compressor of high efficiency generates a large centrifugal force as a rotational shaft rotates at a high speed. In this case, a large amount of oil may be discharged to the outside of the scroll compressor.
Considering this, a technique for preventing excessive discharge of oil has been disclosed. According to the technique, an oil separator is installed at one side of the casing of the compressor, thereby separating oil from a refrigerant to be discharged and collecting the separated oil in the casing before the oil flows to a refrigerating cycle.
FIG. 1 is a longitudinal sectional view illustrating an example of a high pressure type scroll compressor having an oil separator outside of a casing in accordance with the conventional art (hereinafter, referred to as a “scroll compressor”). As shown, in the conventional scroll compressor, a drive motor 20 that generates a rotational force is installed at an inner space 11 of a hermetic casing 10. A main frame 30 is installed above the drive motor 20.
A fixed scroll 40 is fixedly-installed on an upper surface of the main frame 30, and an orbiting scroll 50 is installed between the main frame 30 and the fixed scroll 40 so as to perform an orbital motion. The orbiting scroll 50 is coupled to a rotational shaft 60 coupled to a rotor 22 of the drive motor 20.
The orbiting scroll 50 has an orbiting wrap 52 which forms a pair of compression spaces (P) which move consecutively, by being engaged with a fixed wrap 43 of the fixed scroll 40. In the compression spaces (P), a suction chamber, an intermediate pressure chamber, and a discharge chamber are formed consecutively. In the intermediate pressure chamber, compression is consecutively executed step by step.
An Oldham's ring 70 configured to restrict a rotation of the orbiting scroll 50 is installed between the fixed scroll 40 and the orbiting scroll 50. A suction pipe 15 is penetratingly-coupled to an upper end of the casing 10, and a discharge pipe 16 is penetratingly-coupled to a side surface of the casing 10. The suction pipe 15 is coupled to an inlet 44 of the fixed scroll 40, thereby directly communicating with the suction chamber. The discharge pipe 16 is coupled to an oil separator 90 provided outside of the casing 10.
The oil separator 90 is formed to have a rectangular cylindrical shape, like the casing 10. The discharge pipe 16 is coupled to an upper-half part or portion of the oil separator 90, and an oil collecting pipe 91 configured to collect separated oil in the casing 10 is formed at a lower end of the oil separator 90. A refrigerant pipe 92 configured to guide an oil-removed refrigerant to a refrigerating cycle by being connected to the refrigerating cycle is coupled to an upper end of the oil separator 90.
An unexplained reference numeral 21 denotes a stator, 41 denotes a plate portion or plate of the fixed scroll, 42 denotes a side wall portion or side wall of the fixed scroll, 45 denotes an outlet, 51 denotes a plate portion or plate of the orbiting scroll, 53 denotes a boss portion or boss, 61 denotes an oil passage, 62 denotes a boss insertion groove, 65 denotes a balance weight, and 80 denotes a sub frame.
In the conventional scroll compressor, once a rotational force is generated as power is supplied to the drive motor 20, the rotational shaft 60 transmits the rotational force of the drive motor 20 to the orbiting scroll 50. Then, the orbiting scroll 50 performs an orbital motion with respect to the fixed scroll 40 by the Oldham's ring 70, and forms the pair of compression spaces (P) between the fixed scroll 40 and itself, thereby suctioning, compressing, and discharging a refrigerant.
The refrigerant discharged from the compression spaces (P) is discharged through the discharge pipe 16 via the inner space 11 of the casing 10. The refrigerant discharged through the discharge pipe 16 passes through the oil separator 90 before it moves to the refrigerating cycle. The refrigerant from which oil is separated by the oil separator 90 moves to a condenser of the refrigerating cycle through the refrigerant pipe 92. On the other hand, the oil separated from the refrigerant is collected to or in the inner space 11 of the casing 10 or an oil pump inside of the casing 10, through the oil collecting pipe 91. Such a process is performed repeatedly.
However, the conventional scroll compressor may have the following problems.
First, as the oil separator 90 is installed outside of the compressor, the scroll compressor including the oil separator 90 has an increased size, and vibration noise of the compressor is increased. Further, a space occupied by the scroll compressor in an outdoor unit or device is increased. This may cause the outdoor unit to have a size increase, or a spatial utilization degree may be lowered.
Considering this, the oil separator may be installed in the casing of the scroll compressor. However, in this case, as a driving speed of the scroll compressor is increased to 190 Hz from 160 Hz, a large amount of oil may be discharged together with a refrigerant. In order to solve such a problem, a volume of the oil separator should be increased. However, if the oil separator has an increased volume, a length of the scroll compressor in a shaftwise direction is increased. This may cause a space occupied by the scroll compressor to be increased, and may increase vibration noise of the scroll compressor.